在英语语法中，名词性从句可作为主语、宾语或表语，由引导词和从句组成。常见的引导词包括"That"、"If"、"Whether"等。例如，主语从句"That he is late is a problem"，宾语从句"I know that he is late"，表语从句"His problem is that he is always late"。熟练掌握名词性从句的用法对英语学习者至关重要。
引导词
名词性从句的引导词通常有以下几种：
- That
- If
- Whether
- Who
- Whom
- Whose
- What
- Which
主语从句
主语从句在句子中作主语，常用的引导词有that，whether和if。
例如：
- That he is late is a problem.
- Whether she comes or not is not important.
- If you give him a chance, he will succeed.
宾语从句
宾语从句在句子中作宾语，常用的引导词有that，whether和if。
例如：
- I know that he is late.
- She asked whether I could help her.
- He asked if I had seen the movie.
表语从句
表语从句在句子中作表语，常用的引导词有that，whether和if。
例如：
- His problem is that he is always late.
- The question is whether we should go or not.
- The fact is if you work hard, you will succeed.
